1. Field of the Invention
The present invention relates to a base unit for use in a disk drive apparatus.
2. Description of the Related Art
Disk drive apparatuses, such as, for example, hard disk drive (HDD) apparatuses, are often arranged to rotate disks at high speeds. In such an apparatus, each disk receives resistance caused by a gas enclosed in the apparatus, and this may cause a vibration of the disk and an error in reading or writing, an increase in a power consumption of a motor, or other problems. In particular, in recent years, the storage capacity of HDD apparatuses or the like has been increasing, and the number of disks has been increasing, and it has become important to take measures against the above problems.
Accordingly, instead of air, a gas (which may be hereinafter referred to as a low-density gas) having a density lower than that of air is sealed in a known disk drive apparatus to reduce the aforementioned resistance during rotation of the disk. As this low-density gas, helium or the like is used, for example.
In such a disk drive apparatus, it is important to improve the sealing in of the low-density gas. JP-A 2008-171482, for example, discloses a disk drive apparatus including a base and a cover, and having a low-density gas sealed in a housing space defined by the base and the cover fixed to each other. In this disk drive apparatus, a feedthrough, which is a connector of one type, is joined to the base through a solder so as to close an opening defined in the base to prevent the low-density gas from leaking out of the base through the opening.
However, as noted in JP-A 2008-171482, a flange of the feedthrough and the base have different coefficients of thermal expansion, and therefore, an application of a stress to a solder joint with low stress resistance might cause a crack in the solder joint, resulting in a failure to sufficiently seal in the low-density gas.
It is thus conceivable to use an adhesive which is more resistant to heat shock than the solder and is also inexpensive as a material for joining the base and the connector to each other.